Many medications are administered to patients in a hospital setting on an as-needed basis. One such medication, for example, is a patient controlled analgesia (PCA). For this and many other medications, when a patient has a particular symptom, the patient must call for assistance from a nurse and describe the symptom to the nurse. The nurse must then interpret the description provided by the patient, and select an appropriate medication for that symptom and that patient. In certain instances, the nurse will need to consult with a doctor. The nurse must then retrieve the medication, usually from a remote location such as a nurses' station, and return to the patient's room to administer the medication. In such a procedure, there are a number of steps in which the potential for error is high, such as, for example, the nurse misinterpreting the symptom, or selecting the wrong medication or dosage for treatment of the symptom. Moreover, this process introduces significant delay in the treatment of a patient, frequently prolonging the patient's discomfort.